JPH0646809B2 - Color imaging camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides an optical incidence system inside an outer casing, a filter wheel having a plurality of filter elements, an optical distribution system, and a plurality of image pickup tubes. The present invention relates to a color imaging camera provided.

[Conventional technology]

Current color image pickup cameras usually have three image pickup tubes, which are precisely arranged with respect to an optical distribution system, for example a color separation prism. The scene to be imaged is projected onto the window of the image pickup tube through the optical incident system and the color separation prism. The color separation prism separates the scene to be imaged into red, green and blue frames. A filter wheel having a plurality of filter elements is inserted between the optical incident system and the color separation prism. The filter element can be, for example, a gray filter, a color filter or a special effect filter. By rotating the filter wheel, each of the filter elements can be moved into the optical path.

The filter wheel is mounted on a shaft that is driven via a gear mechanism by an electric motor arranged inside the outer casing of the camera. The size of the filter wheel is limited due to the available space in the camera. Therefore, the number of filter elements in the filter wheel is limited to approximately five. Therefore, it often becomes necessary to replace the filter wheel with other filter wheels or to replace the filter elements in the filter wheel with other filter elements. In either of these cases, it is necessary to remove the filter wheel. However, the axis that drives the filter wheel is located inside the camera and cannot be easily operated (accessed). Therefore, replacement of the filter wheel is a laborious and time-consuming task.

[Object of the Invention]

An object of the present invention is to provide a camera in which the filter wheel can be easily replaced.

[Structure of Invention]

The present invention provides an outer casing, an optical incident system arranged on the optical axis in the outer casing, and an optical distribution system arranged on the optical axis in the outer casing and receiving light from the optical incident system. At least one filter wheel arranged between the optical incident system and the optical distribution system in the outer casing, wherein the optical incident system and the optical distribution system are rotated by rotating the filter wheel. A color including the filter wheel having a plurality of filter elements that can be moved on the optical axis between the plurality of image pickup elements, and a plurality of image pickup elements that are arranged in the outer casing and receive light from the optical distribution system. In the image pickup camera, the filter wheel is arranged in a cassette between the optical incident system and the optical distribution system, and the cassette is inserted or removed through a hole formed in a wall of an outer casing. To be able to The cassette has first and second guide wheels and a drive wheel for holding the filter wheel, and each guide wheel and the drive wheel are in contact with the periphery of the filter wheel. The cassette is further characterized by having an electric motor for rotating the drive wheel.

[Action]

The present invention relates to a color imaging camera having an optical entrance system, a filter wheel having a plurality of filter elements, an optical distribution system, and a plurality of image pickup tubes in an outer casing, and the filter wheel is arranged in a cassette. An electric motor for driving the filter wheel is also arranged in the cassette.

When replacing the filter from the camera, remove the cassette with the filter wheel from the hole in the outer case of the camera,
By exchanging the filter element and inserting the cassette through the hole of the outer casing, the filter element can be easily exchanged with respect to the camera.

The invention holds the filter wheel at its periphery between at least two guide wheels and a drive wheel driven by the electric motor.

When the guide wheel holding the peripheral edge is moved, the filter wheel is released from the holding and can be easily taken out from the cassette, and it is not necessary to remove the driving electric motor or the like. If the filter element is replaced from the filter wheel, the filter element can be replaced.

In another embodiment of the invention, one guide wheel connected to the cassette by a lever loaded by a spring presses said filter wheel against the other guide wheel and drive wheel. . By rotating the lever, the filter wheel is released and easily removed from the cassette and replaced with another filter wheel. The wire spring then pushes the associated guide wheel against the filter wheel again.

In another example of the invention, the filter element is fixed in the filter wheel by a press fit. In this case, applying light pressure to the filter elements causes them to disengage from the filter wheel so that they can be replaced quickly and easily.

In another example of the invention, the filter wheel is provided with a code area for each of the filter elements near its periphery,
The cassette is provided with a reading means for reading the code area. This allows the filter wheel to be programmable so that any desired filter element can be placed in the optical path, since a given filter element is associated with a predetermined code area.

According to another example of the invention, the coded area for each filter element is formed by the presence or absence of holes in the row of positions on the filter wheel, said reading means being provided with a light emitting element and a light sensitive element. It is configured with.

In another embodiment of the invention, holes are drilled in the two outermost positions of the row of positions associated with each filter element, these holes serving to initiate the reading of intermediate positions which determine the type of filter element. To By selecting a predetermined code, the motor is started and the filter wheel begins to rotate. After detecting the relevant code, the motor stops the filter wheel. There are holes at both ends of the code area, and one of these holes starts detection depending on the direction of rotation of the filter wheel.

In another example of the invention, the holes in the two outermost positions also serve to precisely adjust the position of the filter wheel. There is a certain amount of time between the detection of the selected code and the stopping of the filter wheel, especially if the filter wheel rotates rapidly. Therefore, the filter wheel will rotate slightly too much and the selected filter element will not be in the correct position. To eliminate this condition, after the selected code is detected and the motor is stopped, the filter wheel is swung in the opposite direction until the two outermost holes are detected by the associated reading means.

In a further embodiment of the invention, at least a second filter wheel is arranged in the cassette in the same way as the first filter wheel described above, and two filter elements arranged behind the optical entrance system are aligned with each other. So that the center of the second filter wheel is offset with respect to the center of the first filter wheel. By providing the cassette with several filter wheels, the number of filter types formed by the combination of filter elements is considerably increased. The filter wheels are offset from each other so that the code area of the filter wheels can be read.

In another example of the present invention, an inspection slide projector having an inspection slide is provided in the cassette for focusing the image pickup tube. In the camera that is normally used today, the test pattern of the inspection slide is directed onto the semitransparent mirror of the lens element in the optical incident system by the external inspection slide projector of the camera, and then onto the window of the image pickup tube. Projected. Therefore, it is necessary to repeat the adjustment each time the optical incident system changes. By housing the slide projector for inspection in the cassette for the filter wheel, the focusing of the image pickup tube is independent of the type of optical injection system used.

In another example of the present invention, an inspection slide projector includes a projection lamp, at least one lens, and a slide mechanism, and the slide mechanism is movable by an electric motor, and the slide mechanism is incident. Have a mirror and an exit mirror. Since the image of the slide for inspection needs to be projected on the image pickup tube only during the adjustment, a movable slide mechanism is used. When adjusting the tube,
The slide mechanism is moved so that the entrance mirror is in the light beam from the projection lamp. The inspection slide is projected from the entrance mirror through the exit mirror onto the image pickup tube. The inspection slide is arranged in front of the entrance mirror in one example, and is arranged between the entrance mirror and the exit mirror in another example.

In another example of the invention, the test slide comprises two equal parts spaced a certain distance from each other. Focusing of the image pickup tube is performed so that the amplitude of the high-frequency signal extracted from the signal electrode of the image pickup tube becomes maximum when the inspection slide is projected on the image pickup tube. Since the lens system of the inspection slide projector has a relatively small aperture, the depth of focus of the image of the inspection slide projected on the image pickup tube is relatively deep.
Therefore, it is difficult to accurately adjust the amplitude to the maximum. This problem is solved by providing slide strips on each side of the actual slide surface of the inspection slide. In this case, the image pickup tube is adjusted so that the signals of the two slide strips have the same amplitude.

〔Example〕

 The present invention will be described with reference to the drawings.

FIG. 1 is a side view showing a part of a color imaging camera according to the present invention as a partial cross section. The color imaging camera 1 has a box-shaped casing having a rear wall portion 2 and a front wall portion 3.
The front wall 3 has an abutment surface 4 for an optical entrance system 5 shown diagrammatically. The outer casing further has an abutting surface 6 for the color separation prism 7 and the retardation glass plate 8. The color separation prism 7 separates the incoming image information into red, blue and green image information. The three image pickup tubes 9, 10 and 11 are adjacent to the color separation prism 7, and the entrance window of each of these image pickup tubes has a target. Optical axis 12 of optical incidence system 5
And the optical axes 13, 14 and 1 of the imaging tubes 9, 10 and 11
5 is located on the same plane, and the optical axis 12 coincides with the optical axis 13. A cassette 20 is located between the optical incident system 5 and the abutting surface 6. In this cassette 20, the filter element 2
There are filter wheels 21 and 22 having 3 and 24 respectively. One of the filter elements 23 of the filter wheel 21 and one of the filter elements 24 of the filter wheel 22 are selectively positioned in the optical path. The cassette 20 is further provided with a glass plate 55 having a function of increasing the optical path length.
Have. The cassette 20 can be removed from the camera as a unit.

2a is a front view of the cassette 20, and FIG. 2b is a rear view of the cassette 20. The filter wheel 21 has five filter elements 23A to 23E.
2 has five filter elements 24a to 24E. Usually one of the filter elements of each filter wheel is opaque and the other is transparent. The remaining filter elements are gray filters, color filters having different transmission coefficients,
It can be a filter for special effects. The filter wheel 22 is offset relative to the filter wheel 23 so that each time it is rotated, the two filter elements are aligned with each other in the optical path. In Figure 2a, filter element 23A is aligned with filter element 24A (not visible in Figure 2a). Therefore, the filter element 2
Each of 3A-23E can be combined with each of the filter elements 24A-24E, resulting in an extremely large number of combinations.

The filter wheel 21 is held at its periphery between two guide wheels (guide wheels) 25, 26 and a drive wheel 27 driven by a small motor 28. Similarly, the filter wheel 22 is held on its periphery between two guide wheels 29, 30 and a drive wheel 31 driven by a small motor 32. The filter wheels 21 and 22 are made of synthetic resin, and can rotate because they are light in weight. Guide wheels 25 and 29
Is a lever 33 rotatably attached to the cassette 20.
Are linked to. A spring 34 is also connected to the lever 33, by means of which the guide wheels 25 and 2
9 is pressed against the filter wheels 21 and 22. By rotating the lever 33, the filter wheels 21 and 22 are released, and these filter wheels can be easily removed from the cassette 20 and replaced with other filter wheels. Since the filter elements are fixed in the holes of the filter wheels 21 and 22 by a light press fit, the filter elements are fixed by applying a light pressure to these filter elements.
And can be easily removed from 22. This press fit is obtained by three projections 35 provided angularly spaced along the periphery of each hole of the filter wheel, and a recess 36 is formed below these projections. One of these protrusions 35 is shown in FIG. 2c, which is a cross-sectional view of a portion of the filter wheel 21.

Along the perimeter of each of the filter wheels 21 and 22,
A code area 40 is provided for each of the filter elements 23A-23E and 24A-24E. FIG. 2d shows a part of the filter wheel in detail. The code area 40 for each filter element has five positions 41-45. There are holes at the outermost positions 41 and 45 for positioning the filter wheel. The other positions 42, 43 and 44 can be perforated or non-perforated, the presence of holes corresponding to a binary value of "0", the absence of holes corresponding to a binary value of "1". Can be equivalent to or vice versa. Positions 42, 43 and 44 form a code which determines the type of filter element. In FIG. 2d, there is a hole at each of positions 42 and 43 and position 44
There are no holes in this, which represents eg 001. When the filter element is fitted into the filter wheel,
An associated code is determined for each filter element. In order to be able to read the code areas of both filter wheels 21 and 22, both filter wheels 21 and 22
Are laterally offset from each other. Reading of the code area of the filter wheel 21 is performed by five light emitting diodes (LEDs) mounted on the plate 46 and five phototransistors mounted on the plate 49. The plates 46 and 49 are located on opposite sides of the filter wheel 21, respectively. Also, similar means are provided on the plates 47 and 48 for reading the code area of the filter wheel 22. The electric connection line for the reading means and the electric connection line for the small motors 28, 32 are plug 39
It will be terminated inside and the plug will snap into the corresponding socket on the rear wall of the camera when the cassette 20 is inserted into the camera. If it is necessary to move one of the filter elements of one of the filter wheels 21, 22 into the optical path of the image information, the relevant code, for example 001, is set in the control device of the relevant filter wheel, so that each smaller Start the motor (motor) so that the filter wheel begins to rotate. If one of the holes 41 and 45 is detected by one of the two outermost phototransistors, the filter wheel is stopped. However, since there is a certain amount of time between detection and stop, the filter wheel will rotate too much. Thus, after stopping, the filter wheel is swung in the opposite direction until the holes 41 and 45 are detected by the two outermost phototransistors. In this way, each filter element can be accurately moved into the optical path of image information.

The cassette 20 further comprises an inspection slide projector 50, some of which have been omitted from FIG. 2b for the sake of clarity. The slide projector 50 is used for focusing the image pickup tube. This slide projector 50 has a slide mechanism 51, which is driven by a small motor (electric motor) and can be moved in the direction of arrow 52 by a gear 53 that meshes with a rack 54 on the slide mechanism 51. . The gear 53 and the small motor are the second slide b of the inspection slide projector 50.
It constitutes a part of the part shown in the figure. The slide mechanism 51 has a glass plate 55 placed in the optical path during normal operation of the camera. The slide mechanism 54 further comprises an optical part 56 having at least an entrance mirror 57 and an exit mirror 58. FIG. 3 is a sectional view taken along the line III-III in FIG. 2b. This FIG. 3 also shows a portion 60 not shown in FIG. 2b. In this portion 60, a projection lamp 61, a lens 62, and a diaphragm 67 are provided.
The inspection slide 63 is arranged in front of the entrance mirror 57 in the slide mechanism 51. In order to focus the image pickup tube, the slide mechanism 51 is moved to the arrow 5 until the entrance mirror 57 and the inspection slide 63 are positioned behind the squeeze 67.
Move in direction 2. In this case, the exit mirror 58 is located at the center of the optical path. Next, the inspection slide 63 is projected onto the target on the window of the image pickup tube through the entrance mirror 57 and the exit mirror 58. This inspection slide 63 has a test pattern, and scanning an image of this pattern projected on the target will produce a frequency in the signal extracted from the tube. When the image pickup tube is in the focused state (focused state), the amplitude of the signal having the above frequency becomes maximum. However, the optical system of the inspection slide projector that projects the inspection slide 63 onto the image pickup tube has a relatively small aperture. Therefore, the inspection slide 63
However, the depth of focus becomes relatively deep. Therefore, the curve showing the change of the amplitude A as a function of the position X of the target of the image pickup tube changes relatively flat near its maximum value. This curve is shown in FIG. 4a by dashed line 70. Therefore, it is not easy to adjust the image pickup tube to the maximum value M. FIG. 4b is a sectional view showing an inspection slide which facilitates adjustment of the image pickup tube. In this case, slide strips 64 and 65 are provided on both sides of the original slide 63, and these slide strips are provided with the same test pattern instead of the slide 63. The characteristic curves corresponding to these slide strips 64 and 65 are shown in FIG. 4a at 71 and 72, respectively. In this case, the slide strip 64
Focusing of the pick-up tube is achieved by adjusting to a point where the amplitudes of the signals at 65 and 65 are equal, ie at a point N which coincides with the maximum M of the curve 70. Further, the curves 71 and 72 in the region of the point N have a large inclination, and even if the positional change of the image pickup tube is slight, the signal change becomes large, so that focusing of the image pickup tube becomes easy.

FIG. 5 is a sectional view of another example of the slide projector for inspection. In FIG. 5, the same elements as those in the example of FIG. 4a are designated by the same reference numerals as those in FIG. 4a. This example is different from the example shown in FIG. 4a in that the inspection slide 63 is located inside the slide mechanism 51 between the entrance mirror 57 and the exit mirror 58. In this case, it is necessary to provide an additional lens 80 in the slide mechanism.

In the example shown, the cassette has two filter wheels. However, it is of course possible to configure the cassette to have one filter wheel. It is also possible to construct a cassette without a slide projector for inspection. Other various modifications are possible.

〔effect〕

Since the filter wheel and the electric motor that drives the filter wheel are arranged in the cassette, and the cassette can be inserted into or removed from the outer casing, the cassette can be easily inserted into the camera, It can be removed and the filter wheel allows easy replacement of the filter element outside the camera.

The means for supporting and driving the filter wheel (guide wheel and drive wheel) are arranged along the periphery of the filter wheel so that they do not interfere with the insertion and removal of the filter wheel from the cassette. , The filter wheel can be easily replaced.

Since the filter wheel is provided with a code area for each of the filter elements near its periphery, and the cassette is provided with a reading means for reading the code area, a predetermined filter element corresponds to a predetermined code area. The arrangement of the desired filter element in the optical path can be easily implemented by program control.

[Brief description of drawings]

FIG. 1 is a side view showing a part of a camera according to the present invention as a partial cross section, FIG. 2a is a front view showing the cassette of the camera shown in FIG. 1, and FIG. 2b is a cassette of FIG. 2a. FIG. 2c is a sectional view showing a part of the cassette filter wheel shown in FIG. 2a, FIG. 2d is an enlarged view of a part of the cassette filter wheel shown in FIG. 2a, and FIG. Is a cross-sectional view taken along the line III-III in FIG. 2b, and FIG. 4a shows changes in the amplitude A of the signal taken out from the image pickup tube when various inspection slides are used, at the position X of the image pickup tube.
Fig. 4b is a sectional view showing an example of an inspection slide, and Fig. 5 is a sectional view showing another example of a slide projector. 1 ... Color imaging camera, 2 ... rear wall part, 3 ... front wall part, 4,6 ... abutting surface, 5 ... optical incident system, 7 ... color separation prism, 8 ... retardation glass plate, 9 , 10, 11 …… Image pickup tube, 12〜15 …… Optical axis 20 …… Cassette, 21, 22 …… Filter wheel 23, 24 …… Filter element 25, 26, 29, 30 …… Guide wheel 27, 31… … Drive wheel 28,32 …… Small motor (small electric motor) 33 …… Lever, 34 …… Spring 35 …… Projection, 36 …… Recess 39 …… Plug, 40 …… Code area 50 …… Inspection slide Projector 51 …… Sliding mechanism, 53 …… Gear 54 …… Lack, 55 …… Glass plate 56 …… Optical part, 57 …… Injection mirror 58 …… Exit mirror, 63 …… Inspection slide 64,65 …… Slide strips.

Claims (6)

[Claims] 1. An outer casing, an optical incident system arranged on the optical axis in the outer casing, and an optical distribution system arranged on the optical axis in the outer casing and receiving light from the optical incident system. And at least one filter wheel arranged between the optical incident system and the optical distribution system in the outer casing, wherein the optical incident system and the optical distribution system are rotated by rotating the filter wheel. A filter wheel having a plurality of filter elements that can be moved on the optical axis between the two, and a plurality of image pickup elements that are arranged in the outer casing and receive light from the optical distribution system. In a color imaging camera, the filter wheel is arranged in a cassette between the optical entrance system and the optical distribution system, and the cassette is inserted or removed through a hole formed in a wall of an outer casing. You can The cassette has first and second guide wheels and a drive wheel for holding the filter wheel, each guide wheel and the drive wheel contacting a peripheral edge of the filter wheel. The color imaging camera is characterized in that the cassette further has an electric motor for rotating the drive wheel. 2. A color imaging camera as claimed in claim 1, characterized in that two identical or different filter wheels are arranged as said filter wheels in the cassette, offset from one another. And color imaging camera. 3. An outer casing, an optical incident system arranged on the optical axis in the outer casing, and an optical distribution system arranged on the optical axis in the outer casing and receiving light from the optical incident system. And at least one filter wheel arranged between the optical incident system and the optical distribution system in the outer casing, wherein the optical incident system and the optical distribution system are rotated by rotating the filter wheel. A filter wheel having a plurality of filter elements that can be moved on the optical axis between the two, and a plurality of image pickup elements that are arranged in the outer casing and receive light from the optical distribution system. In a color imaging camera, the filter wheel is arranged in a cassette between the optical entrance system and the optical distribution system, and the cassette is inserted or removed through a hole formed in a wall of an outer casing. You can The cassette has first and second guide wheels and a drive wheel for holding the filter wheel, each guide wheel and the drive wheel contacting a peripheral edge of the filter wheel. The cassette further comprises an electric motor for rotating the drive wheel, the filter wheel having one code area along its periphery for each filter element, the cassette further comprising a code area. A color image pickup camera having means for reading the image. 4. A color image pickup camera according to claim 3, wherein each code area is formed by the presence or absence of holes in a row of positions on the filter wheel. Imaging camera. 5. The color image pickup camera according to claim 4, wherein each code area has two outermost positions and a plurality of intermediate positions between these outermost positions, and A color imaging camera, characterized in that a hole is formed at the two outermost positions of each code area to identify the type of filter element associated with the code area and to inform the reading means of reading the intermediate position. 6. A color imaging camera as claimed in claim 3, wherein two identical or different filter wheels are arranged as the filter wheels in the cassette, offset from each other. And color imaging camera.